U.S. Pat. No. 6,528,578 to Wu discloses a golf ball comprising a core and a cover layer wherein the cover is formed of a polyurethane composition comprising a prepolymer comprising a saturated diisocyanate and a curing agent, and an optical brightener.
U.S. Pat. No. 6,506,851 to Wu discloses a golf ball comprising a core and a cover layer wherein the cover is formed of a polyurethane composition comprising a saturated prepolymer comprising an initiated polycaprolactone and a saturated diisocyanate, and a curing agent.
U.S. Pat. No. 7,148,278 to Bulpett discloses golf ball covers formed of a polyurethane composition including a pre-polymer, a curing agent, and a UV stabilizer package for improved color stability.
U.S. Patent Application Publication No. 2012/0100935 to Michalewich discloses a golf ball having a cover material made from a polyurethane or polyurethane/urea hybrid composition. The polyurethane or polyurethane/urea composition is produced by the reaction of an isocyanate blend having an average NCO functionality in the range of 2.05 to 2.35, a polyamine compound, and amine or hydroxyl chain-extender. The resulting cover material has many advantages including improved thermal-stability, durability, toughness, and cut/tear-resistance. The preferred isocyanates in the blend include isophorone diisocyanate (“IPDI”); 1,6-hexamethylene diisocyanate (“HDI”); 4,4′-dicyclohexylmethane diisocyanate (“H12 MDI”); 4,4′-diphenylmethane diisocyanate (4,4′-MDI); toluene diisocyanate (“TDI”); and homopolymers and copolymers thereof.
U.S. patent application Ser. No. 13/534,264 to Michalewich, filed Jun. 27, 2012, discloses methods for making a golf ball having a cover material made from a polyurethane or polyurea composition and the resulting ball. The composition is produced using certain isocyanate blends and curatives containing freezing point depressants.
U.S. Pat. No. 6,939,939 to Slagel discloses a polyurea/urethane material and method for making it provides for improved optical parts. The material allows for ease of manufacture of parts having good optical properties, high hardness, low density, and good impact resistance. The method provides for related manufacturing advantages.
There remains a need for a polyurethane composition containing a UV absorber with reduced migration and surface bloom.